In the manufacture of machinery subject to continuous vibration, it is common to provide additional security to maintain the various bolts in their tightened condition. This is especially critical in the aerospace and aircraft industry, where the loosening of a bolt can have catastrophic results.
The most common apparatus for securing bolts in their tightened positions is safety wire tied between two or more bolt heads. The bolts are specially made with an aperture in the bolt head; the wire being inserted therethrough and looped around each bolt head. In order to maintain a taut wire between the bolt heads, as well as to bias each looped portion towards the machinery, the strands of the safety wire are twisted before being tied to an adjacent bolt. Conventional safety wire pliers are employed to impart this twist from the first bolt to the second. After looping the safety wire about the second bolt head, the strands are twisted in the opposite direction and tied off or tied to a third bolt.
Although the inventor knows of pliers which are utilized in the art of securing safety wires to bolt heads, all such known pliers are only capable of twisting action in a single direction. Thus, after wiring the first bolt head and looping the wire around the second bolt head, the safety wire pliers must be manually twisted in the opposite direction before tying the safety wire.
A second inconvenience of conventional safety wire pliers is that it is necessary to use two hands to manually lock the pliers onto the pair of safety wire strands. Release of the wires is a simpler task, which does not require the use of both hands. This manual locking of the pliers, though not a critical problem, is an inconvenience which decreases the efficiency of the tool in its normal operation.
Another problem common to safety wire pliers known to the inventor is the difficulty in replacing worn out or broken parts thereof. It is typically necessary to replace the entire pair of pliers in such an occurrence.
Therefore, it is a general object of the present invention to provide improved safety wire pliers.
Yet another object is to provide safety wire pliers which are capable of reversible twisting action.
Still another object of the present invention is to provide safety wire pliers with plier arms which will automatically lock when squeezed shut.
A further object of the invention is to provide safety wire pliers which are designed for ease of replacement of the various parts.
These and other objects will be apparent to those skilled in the art.